*{
    margin: 0;
    padding: 0;
}
/*导航栏*/
nav{
    
    width: 1200px;
    height: 100px;
    margin: 0 auto;
    display: flex;
    vertical-align: center;
    align-items: center;
    justify-content: space-between;
    position: relative;
    z-index: 10;
}
nav div{
  height: 20px;
}
nav>div a img{
    width: 134px;
    height: 31px;
}
nav ul{
    display: flex;
    justify-content: space-between;
    width: 600px;
    height: 20px;
}
nav ul li{
    list-style: none;
    position: relative;
}
nav ul li img{
    height: 100%;
}
nav ul li .qrbg{
  display: none;
  width: 128px;
  height: 161px;
  position: absolute;
  background: url(../images/qrbg.png);
  background-size: 128px 161px;
  z-index: 10;
  right: -50px;
  top: 20px;
}
nav ul li:hover .qrbg{
  display: block;
}
nav ul li .qrbg>img{
  width: 117px;
  height: 117px;
  margin-top: 20px;
  margin-left: 6px;
  vertical-align: middle;
  border: none;
}
nav ul li .qrbg>span{
  display: block;
  color: #fff;
  font-size: 14px;
  line-height: 25px;
  text-align: center;
}

nav ul li:last-child:hover{
  background-color: #484848;
}
nav ul li:last-child:hover img:nth-child(1){
  display: none;
}
nav ul li:last-child img:nth-child(2){
  display: none;
}
nav ul li:last-child:hover img:nth-child(2){
  display: block;
}
nav ul li:last-child .top_search{
  display: none;
  width: 320px;
  height: 31px;
  background-color: #484848;
  padding: 5px;
  position: absolute;
  top: 20.1px;
  right: 0;
}
nav ul li:last-child .top_search input{
  width: 320px;
  height: 31px;
  line-height: 31px;
  border: 1px solid #484848;
  background: #fff;
}
nav ul li:last-child:hover .top_search{
  display: block;
}
